1. Field of the Invention
The present invention relates to a backlash absorbing or preventing system for bearings which function to support shafts, stems, axles or any other similar machine elements arranged to be vertically or horizontally swung or rotated.
2. Description of the Prior Art
Shafting which has swinging or rotating motion is widely used in, for example, automobile engines, marine engines, wire connectors in weaving machines, and many other machine components. In general, such shafting is supported upon a bearing. As a result, the journal portion of the shafting and the internal mating portion of the bearing, or the internal circumferential surface of the bushing thereof are inevitably worn out owing to and during the swinging or rotating movement of the shafting, whereby the shafting is caused to undergo a backlash or lost motion within and relative to the bearing. In, for example, a negative type weaving machine such as illustrated in FIG. 1, which is a schematic elevational view of the overall arrangement thereof, a wire connector 8 is connected in one end thereof to connecting wires 7 which connect a shedding motion 5 and a harness frame 2 to each other, while on the other hand, the wire connector 8 is engaged with a shedding lever 6 of the shedding motion 5. In this case, the shedding motion is exemplified in the form of a cam machine. In order to allow the engagement of the wire connector 8 with the shedding lever, the wire connector is usually provided with a bracket which comprises a pair of spaced-apart side plates, and a lever engaging member is arranged between both side plates. With such an arrangement, the shedding lever of the shedding motion is inserted between the side plates of the wire connector, and is firmly mated with the lever engaging member. This engaging member comprises a bearing means, and the bearing means has a supporting shaft pivotably supported thereacross.
A long-term operation of the foregoing type weaving machine arranged as described in the foregoing subjects the outer circumferential surface of this supporting shaft and the inner peripheral surface of the bearing means to wear or abrasion therebetween, particularly in each connecting wire side portion. The reason why the supporting shaft and the bearing means are worn out or abraded, particularly in their portions adjacent to the connecting wires, is that external force acts concentrically upon such portions of the supporting shaft and the bearing means when the weaving machine is in operation.
If the outer circumferential surface of the supporting shaft and the inner circumferential surface of the bearing means are thus worn out or abraded, a backlash is introduced between the supporting shaft and the bearing means as described in the foregoing. In the foregoing type of weaving machine, such a backlash causes the supporting shaft to be reciprocatively moved horizontally or vertically in proportion to the backlash of the supporting shaft relative to and within the bearing means as a result of the swinging movement of the shedding lever, and an extreme vibration or shake occurs in the connecting wire joined to the wire connector in which the supporting shaft and the bearing means are provided. This causes the connecting wires to undergo great impact force and consequently to be slackened. If the slack of the connecting wires become greater with the operation of the weaving machine, the connecting wires are subjected to vibration and impact force, which are also proportionally still more increased. As a result, the connecting wires undergo rupture. This disadvantage is more conspicious in weaving machines of recent years which are operated at a far higher speed.
The weaving machine is also available as the positive type as well as the foregoing negative type. In a positive type weaving machine such as shown in FIG. 23, a pair of interlocking leverage means 93, 93 of an L-shaped configuration are connected to each other by using a horizontal linking rod 92, and are joined to the harness frame 2 through vertical linking rods 94, 94. The left-hand side one of both interlocking leverage means 93 is connected to the shedding motion 5 by means of an actuating linking rod 95 through the shedding lever (not shown).
The leverage means are arranged to pivot about supporting shafts 16. The supporting shafts are worn out or abraded as well as mating bearing means provided in the leverage means while the weaving machine including the leverage means is operated over a long period of time. A backlash is thus created between the supporting shaft and the bearing means also in the positive type weaving machine. This causes the shedding motion to fail to achieve a predetermined amount of warp shedding, and any resulting sheds in the warps are decreased in size. Also, the backlash between the supporting shaft and the bearing means introduces vibration and noises in the operation of the weaving machine.
The negative type and the positive type weaving machine are respectively subjected to a backlash between the shafting and the mating bearing means as described in the foregoing.
Such a backlash is not limited in the occurrence thereof to the weaving machines. For example, automobile engines and marine engines also undergo this kind of backlash.
As illustrated in FIG. 25, the automobile engines and the marine engines comprise a piston 100 and a connecting rod 96 in addition to a cylinder (not shown). The connecting rod 96 is provided with a big end portion 97 having a semi-circular configuration, and forms a bearing inserting aperture 41a with a bearing cap 98. In FIG. 26, a crankshaft 99 is shown which comprises a crankpin 16a, and this crankpin 16a is inserted through the bearing inserting aperture 41a. The bearing inserting aperture 41a is fitted with a bearing metal on the inner circumferential surface thereof. A backlash is created between the crankpin 16a and this bearing metal.
This backlash causes the automobile engines and the marine engines to undergo critical trouble in which the piston stroke is not accurately reflected in the rotation of the automobile wheel and the marine propeller. Also, the backlash between the crankpin and the bearing metal in the bearing inserting aperture of the connecting rod makes much more noise in the operation of the automobile and marine engines. Moreover, this backlash threatens damage of the crankpin.
As is apparent from the foregoing Description of some examples, the mechanical engagement of the shafting and the mating bearing means with each other is inevitably subjected to a backlash as a result of their wear or abrasion. However, in spite of this fact, the prior art has not made any system or provisions for absorbing or preventing a backlash in such a mechanical engagement. For this reason, some backlash absorbing useful system or means has been desired to be provided for bearings in many mechanical industries.